The present invention is directed to a method and apparatus for packaging a product, and, more specifically, toward a method and apparatus for transferring a plurality of stacks of discrete objects supported by a platform from the platform to a box while maintaining the integrity and arrangement of the stacks.
Various packing or packaging machines are known for placing a product into a box, carton, or other container. However, special problems are encountered when the product to be packaged comprises stacks of discrete objects. These stacks, for example, may have previously been formed by a stacking machine and set on a support surface for further processing. Such stacks can be lifted manually and placed into a box, but if multiple stacks have to be placed in the same box, it can be difficult to maintain the integrity of the stacks as they are moved; this leads to the occasional need for a manual restacking step. Furthermore, it is difficult to lift multiple adjacent stacks of objects at the same time by hand, and therefore a person would normally be limited to lifting the stacks one at a time when placing them in a box. However, if the stacks are to be packed tightly in the box, that is, if they are to be packed with a minimal amount of space between the stacks themselves and between the stacks and the inner walls of the box, it may be difficult to manually position the stacks that are adjacent a sidewall, and especially difficult to place the last stack into a box, which stack will be bounded on four sides by box sidewalls or other stacks of products.
Stacks of products such as those discussed above can be moved by gripping the top and bottom of the stack and applying pressure to hold the stack together while it is moved. An apparatus for gripping and moving stacks in this manner is disclosed in a co-pending application entitled xe2x80x9cStack Transfer Devicexe2x80x9d filed concurrently herewith and assigned to the assignee of this application, the disclosure of which is hereby incorporated by reference. However, gripping a stack from the top and bottom makes it difficult to insert the stack into a previously formed box having an open top. To package a stack that is gripped in this manner, either a box must be formed around the stacks of objects while they are being gripped, or the objects must be deposited on a surface and moved again from the surface to a box.
When using a stack transfer device, such as the one disclosed in the above application, the stacks are often placed on a device called a matrix former before they are packaged. A matrix former comprises a horizontal platform and two or three upstanding, movable sidewalls forming a structure that resembles a cube with an open top and no front wall. The purpose of the matrix former is to consolidate several stacks by sliding them toward one another and removing the spaces therebetween, to make them easier to fit into a box. The upstanding walls of the matrix former, however, make it even more difficult to transfer the stacks from the matrix former to a preformed box or case. It would therefore be desirable to provide a method and apparatus for automatically, simultaneously, transferring a plurality of stacks of discrete objects from a support platform, such as a matrix former, to a box in a manner that preserves the integrity and arrangement of the stacks.
These problems and others are addressed by the present invention which comprises a method and apparatus for transferring objects, and especially multiple stacks of discrete objects, from a support surface to an open-topped box. While the present invention could be used in a number of environments, it finds particular use in transferring stacks of frozen hamburger patties from a support surface having upstanding walls to an open-topped cardboard box and will be described in terms of such as system, it being understood that the invention is by no means limited to use in such environments.
The preferred embodiment of the invention comprises a first generally horizontal platform, which forms a part of a matrix former, on which a plurality of stacks of discrete objects are to placed, and a second platform for supporting a box into which the stacks are to be packed. The second platform is movable vertically and can also be pivoted about an axis parallel to its box-contacting surface. The second platform includes at least one gripper for holding the bottom of the box securely against the box-contacting surface and, preferably, also includes a plurality of fingers for engaging the top edges of the box to control the movement of the box and to hold down flaps extending from the top edge of the box. The box-contacting surface of the second platform also preferably includes a plurality of rollers that allow an empty box to roll on and off the platform when the platform is inclined.
In operation, the second platform is aligned with a conveyor that feeds empty boxes one at a time. A box rolls onto the second platform and is gripped by at least one gripper on the second platform to hold it in place, with its bottom on rollers and its open top facing away from the rollers. The second platform is then pivoted 180 degrees to an inverted position, with the open box top positioned over and facing down towards the first platform above the stacks of objects on the first platform. The second platform is next lowered over the stacked objects, until the first platform is about even with or slightly inside the top opening of the box so that the stacks of objects are disposed completely within the box. The orientation of the stacked objects is maintained by the walls of the box and the platform. The first and second platforms are pivoted together, until the top opening of the box is again facing upwardly and the objects are supported on the closed bottom of the box rather than by the first platform. The second platform and box are moved away from the first support, so the first support may return to its original orientation. The second support is then moved to a discharge location where it tilts to slide the fully loaded box onto a conveyor for further processing, and finally the second support returns to its original position to receive another empty box from the feeding conveyor to start the process again.
It is therefore a principal object of the present invention to provide an apparatus for packing a plurality of stacks of discrete objects in a container.
It is another object of the invention to provide an apparatus for transferring a plurality of stacks of discrete objects from a platform to a box while maintaining the integrity and mutual relationship of the stacks.
It is a further object of the invention to provide a method for packing a plurality of stacks of discrete objects in a box.
It is still another object of the invention to provide a method of packing stacks of discrete objects supported by a platform having at least one upstanding sidewall taller than the stacks of objects.
It is yet another object of the invention to provide an apparatus for simultaneously boxing a matrix of discrete objects.
In furtherance of these objects, a packing apparatus is provided that includes a first platform having a product contact surface. The first platform is pivotable about an axis parallel to and spaced from the product contact surface between a first position, wherein the product contact surface faces in a first direction, and a second position, wherein the product contact surface faces in a second direction. The apparatus also includes a second platform comprising a box support having a box contact side and a box holder for holding a box on the box support. The second platform is movable between a first position and a second position, and the box support is pivotable between a first angular orientation and a second angular orientation.
Another aspect of the invention comprises a method of packing a product that involves providing a first platform having a product support surface facing in a first direction and placing a product to be packaged on the product support surface. A second platform including a box support having a box contact surface is aligned with a first conveyor and receives a box having a closed bottom and an open top. The box is secured to the box support with the closed bottom in contact with the box contact surface. The box support is pivoted so that the box contact surface faces the first platform product support surface and the box open top faces the product. The second platform is moved towards the first platform until the product passes through the box top opening, and the first platform and the box support platform are pivoted until the box open top faces in the first direction. The second platform is moved away from the first platform, and the first platform is pivoted until the product support surface faces in the first direction. The second platform is aligned with a second conveyor, and the box is released onto the second conveyor.
Another aspect of the invention comprises a packing apparatus that includes a first platform having a product contact surface that is pivotable, via an actuator, about an axis parallel to and spaced from the product contact surface between a first position, wherein the product contact surface faces in a first direction, and a second position, wherein the product contact surface faces in a second direction. The apparatus also includes a second platform that includes a box support having a first wall and a box contact side and a positioning device for positioning and holding a box on the box support. The positioning device includes a second, movable, wall and an actuator for moving the movable wall with respect to the first wall. At least one gripper is also provided for gripping an edge of a box having a closed bottom and open top on the box support. The second platform is movable between a first position and a second position, and the box support is pivotable between a first angular orientation and a second angular orientation with respect to said first platform. The apparatus also includes at least one guide track for guiding the movement of the second platform between the first position and the second position, a drive belt extending between a first wheel and a second wheel, and a drive operably coupled to the drive belt. The second platform is coupled to the drive belt.